Mechanism for power shovels and cranes



Aug. 31 1926.

c. A. WEBER MECHANISM FOR POWER SHOVELS AND CRANES Filed Oct. 5, 1921 2. snee ts-sneet 1 CHARLES A. WEBER INVENTOR.

By W *6 21.

144) I ATTORNEYS Aug. 31 1926.

C. A. WEBER MECHANISM FOR POWER SHOVELS ANDCRANES Filed O t 5, 1921 2 Sheets-Sheet 2 l l. lllllllll. |l||.||| ||||||J CHARLES A. WEBER INVLNTOR.

744/5 ATTORNEYS.

Patented Aug. 31, 1926.

UNITED STATES 1,597,745 PATENT OFFICE.

CHARLES A. WEBER, OF LORAIN, OHIO, ASSIGNOR TO THE THEW SHOVEL COMPAN OI LOBAIN, OHIO, A CORPORATION OF OHIO.

MECHANISM FOR POWER SHOVELS AND CBANES.

Application filed October 3, 1921.

My invention relates to improvements in mechanlsm for power shovels and cranes,

and more particularly to such mechanisms as are especially adapted to elevate a bucket or dipper to a predetermined elevated position, or to lower the same, at will when the frame or shovel is operated by the power of an explosive engine or an electric motor, as distinguished from those shovels and cranes which are operated by steam power.

It is an object of my invention to provide for such mechanisms having such a source of power the same features of control as are had in the case of steam shovels or cranes, wherein it is possible to hold the shovel or dipper in a predetermined elevated forward position by the pressure of the steam exerted against the piston of a small engine heretofore provided in such steam-operated mechanisms, and usually carried on the boom thereof.

Although my invention isnot limited thereto, it is particularly applicable to such power shovel mechanisms as are well known in the art and are so constructed that the shovel may be projected forwardly by the action usually of a gear pinion and rack, the pinion being carried by the boom and being known as the shipper shaft pinion, and the rack being carried on the shovel-supporting thrust arm or dipper stick. The pinion by co-operating with the dipper stick rack causes the dipper stick to be reciprocated forwardly or rearwardly, as may be desired, in the operation of using the power shovel. In such a mechanism when the dipper stick has-been forwardly extended to.

a forward osition and the power released, the force 0 gravity increased by the weight of the excavated material contained in the bucket or dipper tends to cause the dipper stick to recede from its forward position, and it is an object of this invention, therefore, to automatically brake the shipper shaft upon the start of any such recessional motion by the dipper stick.

Another object of my invention is to cause the automatic release of such a brake when the dipper stick is again advanced forwardly. 7

Another object of my invention i to provide a manually operated lever for tripping the brake, to make it inoperative.

Another object is to use the same lever Serial No. 504,996.

that is used to associate the source of power with the shipper shaft, in order to rotate the same in the one or other direction, to advance the shovel, or to withdraw the same, for the purpose of tripping the brake mechanism whenever it is desired to operate this lever, in such a direction as will cause the shovel to withdraw from the forward position by power from the source of power provided.

Anothe object of my invention is to cause the brake to be tripped by the lever when the lever is slightly moved towards the dipper withdrawing position, and to cause the said lever, upona continued movement in the same direction, to apply the power to rotate the shipper shaft in such a direction as to withdraw the dipper from a forward position to a rearward position.

Other objects of my invention and the invention itself will become' apparent as the description thereof progresses, and in which description reference will be had to the accompanying drawings illustrating an embodimentof my invention, and in which drawings Fig. 1 is a side elevational view of a per tion of a power shovel mechanism embodying my invention.

Fig. 2 shows a plan view of a portion of the boom mechanism illustrated in Fig. 1.

Fig. 3 shows a side elevational view of the parts illustrated in Fig. 1, together with certain additional parts Fig. 4 is a detail showing a source of power connected through a conventional reversing mechanism to the driving gear, and

also shows means connected with a lever for actuating the reversing mechanism.

Referring now to the figures of the drawing, in all of which figures like parts are indicated by like reference characters, at 2 is shown a boom structure carrying on its end sheaves 3 and pivoted at 4 to the frame 5 of. the ower shovel main supporting frame. This frame is adapted to carry the motor means for performing the workof advancing and elevating the power shovel, and to do such other work as rotatin the boom frame carrying the boom, etc. uch motor means ma be an electric motor or gas engine for tie embodiment illustrated, or any othr suitable source of power. In the power shovel mechanism of the drawings this source of power is utilized as well to advance the shovel 12 carried by the boom 2 forwardly, as illustrated in Fig. 1, or to withdraw the shovel rearwardly from its illustrated position, the power being communicated from the source of power by a mechanism comprising the sprocket wheels 15, 16, 17 and 18 and power transmitting chains 19 and 20, and by gear pinions 21, 22 and 23 to a rack 24, which is carried on the power shovel stick or shovel thrust arm 14, the rack 24 engaging the pinion 23, the pinion 23 being known as the shipper shaft pinion and the shaft 9 upon which it is mounted being known as the shippers shaft. This construction is well known in the art, as is also that construction thereby by means of a cable 25 passing over a sheave 3 and a sheave contained in the sheave block 26 the shovel 12 may be elevated or lowered, the sheave block 26 being pivoted at 11 to the shovel and the sheave 3 being carried on the shaft 10 at the end of the boom 2.

Also that construction of the prior art whereby an operators hand-lever 27, carried on the frame 5 and rotatably connected thereto by a lever journal member 28, 1s adapted, upon a forward movement of the lever 26, to operate a clutch (not shown in the drawings) which will operativelyconnect the motor-shaft with the sprocket wheel 15 in such a way as to drive the sprocket wheel 15 in a clockwise direction, so that by mean of the chains 19 and 20 and the sprocket wheels'16, 17 and 18 the shaft 29, carrying the sprocket wheel 18, will be rotated likewise in a clockwise direction. The gear pinion 21, which is likewise carried on the shaft 29, will also be rotated in a clockwise direction to cause theengaged pinion 22, carried on the shipper shaft 9, to be rotated in a counter-clockwise direction, and the shipper shaft pinion 23 being rotated with the pinion 22 and having its teeth in engagement with the teeth of the rack 24 on the shovel arm 14 will cause the shovel arm to be forwardly advanced.

The usual construction of such power shovel mechanisms is herein assumed to be employed, whereby the hand lever 27 being moved rearwardly will cause a different clutch to associate the operating motor to the shaft of the sprocket wheel'15, rotating it in the opposite direction, that is, in a counter-clockwise direction, whereby through the chains, sprockets and gear pinions, above referred to, the shovel arm 14 will be reciprocated rearwardly to withdraw the shovel 12 from a forwardly advanced position. The lever 27 has before been used to advance or to withdraw the shovel arm, as above described. I employ uch previous structure whereby this is accomplished, and also use the same lever 27 for another purpose, which will be later described, but

which briefly consists in unlocking the mechanism to permit the shovel to take a rearward position.

The shovel is advanced to a forward position, such as that illustrated in Fig. 1, by throwing the lever 27 to a forward position. Now, if the operator withdraws the lever 27 to its intermediate, illustrated neutral position, the shovel 12 would ordinarily, by the force of gravity, take such a position wherein the shovel would be substantially below the sheave shaft 10; that is, where the center of gravity of the shovel and the shovel arm were to take such a position directly below the supporting sheave 3. In order to prevent thisI have provided a brake mechanism, comprising a brake drum 40 and a contracting brake band 41, the brake band encircling the drum 40 and being normally, when in inoperative position, only in slight contact therewith, the amount of contact being adjusted by adjusting nuts 42 and 43 placed on either side of a block 44, the block having stems 45 on either side thereof, and which stems are journalled in a brake-operating arm 46.

The block 44 has a longitudinal bar to admit the bolt member 47, which passes thercthrough, being secured to the block 44 by the adjusting nuts 42 and 43. Thus the bolt 47 is pivoted at 45 to themember 46; the bolt 47 is pivoted at 48 to one end 'of the brake band 41, and the member 46 is pivoted at a point 49 to the other end, the pivot points 45 for the block 44 and 49 for the end of the brake band being relatively close together on the member 46 and the bolt 47 extending in a direction nearly tangent to an extension of the line of curvature of the brake band. The member 46 at its other end extends into a. block 13 carried on the boom 2, the said block having a turnedup portion 50 and an elongated perforation 51, this perforation being for the purpose of permitting a pin 52, carried by the member 46, to reciprocate up and down in the said elongated perforation to limit the motion of the member 46in either determined maximum.

The arrangement of the brake band and the means secured thereto, comprising the bolt 47 and member 46, by joints 48, 49 and 45, causes the brake band to have a locking action when the drum 40, which make frictional, contact with the band 41, is rotated in a counter-clockwise direction. This is the rotational direction which would be given to it by the action of the shovel arm being rocked rearwardly, due to the effect of gravity, after having been extended to a forward position. This action can be well understood by considering that when the drum 40 is. rotating in a counter-clockwise direction. the band 41 making frictional contact with the drum will wrap itself direction to a pre- -maximum friction occurs,

tightly around the drum and the arrangement of the members 46 and 47 and the block 51 is such that the friction of the band on the drum constantly increases until a wherein the shovel stick or arm is positively braked or held against further backward movement, and this occurs before the ,shovel has been moved rearwardly any substantial amount. During this braking action the member 46 will be projected downwardly toward the limiting set screw 71, which is adapted to be adjusted towards or awa from the member 46, so as to limit its ownward movement any predetermined amount, it being desirable to limit its downwardmovement to a point where the braking is efficiently accomplished. but beyond which point the braking would be so severe that a very strong effort would be required order to unlock the brake. In order to unlock the brake, means are provided whereby the member" 46 is lifted.

The member 46 has a turned-down portion 53. A crank lever 54 pivoted at 55 and operable by a rod 56 pivoted to it at 57 is adapted to move the member 46 u wardly by its arm 57, pressing against t e edge 58 of the member 46 when the rod 56 is drawn rearwardly. The lever 27 has connected to it a cam member 59 at the end of which a rotatable roller 60 is placed. A crank lever 61 is journalled to the boom frame at 62 and has one arm 63 extending in the path of the roller 60 when the lever 27 is drawn rearwardly and the other arm 64 of the crank lever 61 is journalled at 65 to the tie-rod 56 connecting with the crank lever 54.

When the lever 27 is drawn rearwardly, rod 28' which is connected to one arm 0 a bell crank 73, rocks the bell crank on the pivot 74 and causes arm 75 of the crank to shift bevel gears 76 and 77 toward the gear 15. This action causes gear 76 to mesh with the large bevel gear-78 keyed to a motor shaft 7 9 and to be rotated thereby in one direction, thus causing the armand dipper to be moved nearwardly. When the lever 27 is moved forwardly, bevel gear 77 meshes with the large gear 78 and causes the gear 15 to rotate in the opposite direction thereby causing the arm and dipper to be extended forwardly. It will be noted that the sleeve 80 carrying gears 76 and 77 is slidably mounted on shaft 72 and is held for rotation with the shaft by means of a longitudinal key 81. A collar 82 rotatable with the sleeve connects with the arm of the bell crank so that the sleeve and gears 76 and 77 may be shifted thereby.

When the lever 27 is drawn rearwardly on its pivot 28, so that the roller 60 engages with the arm 63 of the crank lever 61, raising the said arm, the arm 64 will be was...

drawn rearwardly, as a result of which there will be a pull on the tie-rod 56, to cause the contacting end 57 of an arm of the crank lever 54 to engage the edge 58 of the member 46 and the member 46 will thus be raised. This will unlock the brake band 41, since the raising of the member 46 will expand the band and the point 49 and 48 will be separated instead of being drawn closer together as during the breaking operation.

If thelever 27 is only drawn rearwardly sufficiently to unlock the brake 41,.but not sufiicient to operate the clutch mechanism to cause the shipper shaft pinion 23 to propel the shovel arm 14 rearwardly, the shovel arm will, under the force of gravity, take a more rearward position, until the center of gravity of the shovel and arm is below the sheave 3. Now, upon a continued movement of the lever 27 rearwardly, the shovel arm withdrawing clutch will be 0 erated to associate the source of power, w ich will be an electric or explosive motor, with the shaft 72 for the sprocket wheel 15 and the sprocket wheel will be rotated to rotate the shipper shaft pinion 23 clockwise to cause the shovel to be withdrawn from the forward or intermediate position in which it is placed to a more rearward position. At the same time the operator may, b means of other levers not shown, lower t e bucket or raise the same, as may be most desirable under operating conditions or the work being done.

By virtue of the above-described brake mechanism, the brake will always be set upon a rearward movement of the shovel arm, and will always be expanded upon a forward movement of the shovel arm, so that for successive forward movements of the arm it will not be necessary to trip the f brake by means of the tripping lever 61 and associated mechanism.

Having thus described my invention in a specific embodiment, I wish it to be understood that numerous and extensive departures may be made from such embodiment, but without departing from the spirit of my invention.

\Vhat I claim as my invention is;

1. In a power shovel mechanism, the com bination with a boom, a dip er, a dipper arm, said arm carrying the ipper at one end, co-operating mechanism on the dipper arm and the boom for reciprocating the said arm forwardly "and rearwardly, power means to cause the said mechanism to reciprocate the arm forwardly, an automatic brake operated by the reversal of said mechanism which occurs by force of gravit after the saidpower means is disassociate from the said co-operating mechanism to automatically hold the arm in its forwardly extended position against the force of gravity, a pair of clutches adapted to associate said power means with the said co-operating mechanism,

one of which is adapted to cause the said power means to drive the co-operatlng mechanism in such a direction as to advance the said dipper arm, and the other clutch being adapted to cause the said power means to drive the said co-operating mechanism in such a direction as to move the said arm and carried dipper rearwardly, a manually operated lever adapted to be moved in two directions, means responsive to the movement of the lever in one direction to operate one of the said clutches, and means responsive to the movement of the lever in the other direction to operate the other of the said clutches, neither of the said clutches being operative when the lever is in an intermediate position, said manually operated lever being adapted to trip the said brake to make it inoperative just previous to the engagement of said clutches.

2. In a powershovel mechanism, the combination with a boom, a dipper, a dipper arm, said arm carrying the dipper at one end, co-operating mechanism on the dipper arm and the boom for reciprocating the said arm .forwardly and rearwardly, power means to cause the said mechanism to reciprocate the arm forwardly, a brake automatically applied by the rearward movement of the said arm after the said power means is disassoeiated from the said cooperatingmechanism to automatically hold the arm in its forwardly extended position against the force of gravity, a pair of clutches adapted to associate said power means with the said co-operating meeha nism, one of which is adapted to cause the said power means to drive the co-operating mechanism in such a direction as to advance the said dipper arm, and the other clutch being adapted to cause the said power means to drive the said co-o'perating mechanism in such a direction as to move the said arm and carried dipper rearwardly, a manually operated lever adapted to be moved in two directions, means responsive to the movement of the lever in one direction to operate one of the said clutches,

means responsive to the movement of the lever in the other direction to operate the other or" the said clutches, neither of the said clutches being operative when the lever is in an intermediate position, and means associated with the said manually operated lever operable when the said lever is moved from neutral position in the direction of the dipper arm rearward movement operative position to trip the said brake.

3. In a power shovel mechanism, the combination with a boom, a dipper, a dipper arm, said arm carrying the'dipper at one end, co-operating mechanism on the dipper arm and the boom for reciprocating the said arm forwardly and rearwardly, power means to cause the said mechanism to reciprocate the arm forwardly, a brake automatically operated by the rearward movement of the said arm after the said power means is disassociated from the said cooperating mechanism to automatically hold the arm in its forwardly extended position against the force of gravity, a pair of clutches adapted to associate said power means with the 'said co-operating mechanism, one of which is adapted to cause the said power means to drive the co-operating mechanism in such a direction as to advance the said dipper arm, and the other clutch being adapted to cause the said power means to drive the said co-operatin'g mechanism in such a direction as to move the said arm and carried dipper rearwardly, a manually operated lever adapted to be moved in two directions, means responsive i to the movement of the lever in one direction to operate one of the said clutches, means responsive to the movement of the lever in the other direction to operate the other of the said clutches, neither of the said clutches bein operative when the lever is in an interme iate position, and means associated with the said manually operated lever operable when the said lever is moved from neutral position in the direction of the dipper arm rearward movement operative position to trip the said brake, said brake tripping means being operative before the operation'of the clutch under the control of the common manually operated lever.

In witness whereof, I have hereunto signed my name this 25th day of September, 1921.

CHARLES A. W'EBER. 

